Dhaka: 10:25 AM, Tue, 19 Jun, 2018

400yr old sharks could hold secret to long life

Mukul : risingbd.com
Publish on: 2017-07-07 11:33:58 AM     ||     Updated: 2017-07-07 10:39:58 PM

Risingbd Desk: They are the longest living vertebrate on Earth, with incredibly long lifespans of up 400 years.

And now researchers believe that Greenland sharks could hold the secret to long life in humans.

Scientists are mapping the DNA of the sharks in the search for 'unique genes' which could hold the secret to the shark's longevity.

Researchers from the Arctic University of Norway have sequenced the DNA from Greenland sharks – some of which were alive in the Georgian era.

Greenland sharks are found in deep water in the Atlantic Ocean, from Canada to Norway, and little is known about their biology and genetics.

The team collected DNA from tiny clippings from the fin of the sharks, which are caught on a line live, and tagged before being released.

Using this DNA, the researchers have sequenced the full genome from almost 100 Greenland sharks.

And they are now attempting to find the genes that hold the secret to why the sharks live so long.

Speaking at a conference in Exeter, Professor Kim Praebel, who is leading the study, said: 'This is the longest living vertebrate on the planet.

'Together with colleagues in Denmark, Greenland, USA, and China, we are currently sequencing its whole nuclear genome which will help us discover why the Greenland shark not only lives longer than other shark species but other vertebrates.

'The results we presented here in Exeter will help us understand more about the biology of this elusive species.'

If found, the 'long-life' genes could shed light on why all vertebrates have a limited life span, and what dictates the life expectancy of different species, including humans.

While the researchers are still looking for the 'long-life' genes, their study has also shed new light on the shark's behaviour, and how it is related to other members of its species living thousands of kilometres away.

Professor Praebel said: 'Since the Greenland shark lives for hundreds of years, they also have enough time to migrate over long distances and our genetic results showed exactly that.

'Most of the individuals in our study were genetically similar to individuals caught thousands of kilometres away.

'We still do not know where and how the Greenland shark reproduce, but the results we presented here in Exeter showed that the shark may prefer to mate in deep hidden fjords of the Arctic.'

Professor Praebel added that sharks are living time-capsules that could help uncover the impact of man on the oceans over time.

Tissues, bones, and genetic data from the shark could help measure the impact of climate change on the population, when and how contaminants and chemical pollution from industry began to affect the oceans, and the extent to which commercial fishing over hundreds of years has affected the shark population.

He added: 'The longest living vertebrate species on the planet has formed several populations in the Atlantic Ocean.

'This is important to know, so we can develop appropriate conservation actions for this important species.'

Source: The Mail

Risingbd/July 7, 2017/Mukul